Methotrexate use in fathers

Date: September 2024, Version 4.0

What is it?

Methotrexate (Maxtrex®, Metoject®) is used to treat auto-immune illnesses such as Crohn’s disease, rheumatoid arthritis and psoriasis, and in the treatment of certain types of cancer.

Should methotrexate be used by the male partner while a couple is attempting to conceive?

Because of the way that methotrexate works, there are theoretical concerns that it could damage sperm, and potentially affect the development of a baby conceived while the father is using it.

Pregnancies fathered by around 1,000 men who were using methotrexate around the time of conception have been studied. There are no concerns of links with miscarriage, stillbirth, birth defects, low infant birth weight, or preterm birth. While this is reassuring, more information about pregnancies fathered by men using methotrexate needs to be collected to confirm that there are no problems.

As a precaution, the manufacturers of methotrexate usually advise that couples, where the male partner takes methotrexate, use effective contraception and wait at least three months after the man stops methotrexate treatment before attempting to conceive. This is because it takes approximately three months for a sperm to form.

In practice, there is no evidence of pregnancy problems caused by the father using methotrexate. Therefore, if a couple is planning a pregnancy and the man’s medical condition is well-controlled with methotrexate, a specialist will be able help them weigh up the potential risks and benefits of continuing the medication so that informed decisions can be made about treatment. Do not make any change to your medication without first talking to your doctor.

Will the baby need extra monitoring during pregnancy?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. No additional monitoring of pregnancies conceived while the father was using methotrexate are required.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.